As a technique for improving on-ice and on-snow performance of a pneumatic tire, sipes are provided on the tread surface in order to ensure an edge component while suppressing a reduction in the footprint area. Upon increasing the number of sipes in order to increase the edge component, however, the block rigidity is reduced, making it impossible to achieve sufficient block durability.
To address this problem, JP 2008-120174 A (PTL 1) proposes a pneumatic tire in which circumferential sipes that divide each of the blocks forming the land portion rows of the tread surface into two small blocks are provided. Each circumferential sipe is constituted by a sipe parallel section that extends in parallel to the tread circumferential direction and a sipe inclined section that extends at an inclination to the tread circumferential direction. The sipe depth of the sipe inclined section is less than the sipe depth of the sipe parallel section.